Calibrating Differential Pressure (Dp) - ABB XRC G5 User Manual

Close both the downstream and upstream tap valves.
Open the atmosphere vent valve.
Click Low Cal Point. Verify the current reading is continuously updated. This should
represent the lowest calibration point.
When the current reading stabilizes, click OK; otherwise, enter a different value, and then
click OK.
After the previous value is accepted, the next calibration point button will automatically
activate. Click the activated button.
IMPORTANT NOTE: This procedure details the calibration procedure for a three (3) point
calibration. Available pressure points will be displayed in the calibration window and will
become active in the prescribed calibration order: Low Cal Point, 100% Cal Point, and 50%
Cal Point.
Although these instructions are specific to a three (3) point calibration, for a five (5) point
calibration, enter 5 values.
Connect the calibration standard to the calibration test port.
Close the atmosphere vent valve.
Apply pressure to 100% of the transducer range (URL or 100% of the target value).
When the current reading stabilizes, click OK; otherwise, enter a different value (pressure
value from the calibration source), and then click OK.
After the previous value is accepted, the next calibration point button will activate. Click
the activated button.
Apply pressure to the next target value as shown in the Calibration window.
In a 3-point calibration, this will be the final calibration point and is equal to 50% of the URL of the
transducer. The pressure value for 50% of the URL will be displayed in the window.
Example: If the transducer has a URL of 1500, then 50% of that pressure, or the Target pressure, is
750.
In a 5 Point calibration, this will be the third value and will be equal to 75% of the transducers URL.
Example: If the transducer has a URL of 1500, then 75% of that pressure, or the Target pressure, is
1125.
When the current reading stabilizes, click OK; otherwise, enter a different value (pressure
value from the calibration source), and then click OK.
IMPORTANT NOTE: For a 3-point calibration, SP calibration is now complete. A 5 Point
calibration requires two more points to be calibrated: 50% and 25%.
Repeat steps 19 through 21 until all calibration points have been pressured.
11.1.4

Calibrating differential pressure (DP)

A three- or five-point pressure method is used to calibrate the flow computer DP cell. Different
pressures are applied to the cell from a known, traceable source, with resultant pressure values
entered in the flow computer using PCCU32 software.
During factory calibration, any differential pressure (DP) shifts resulting from a static pressure effect
are corrected. These corrections are not user-configurable and cannot be modified by a field or user
calibration. This ensures that the readings received in the field are accurate. The factory set shift is
also not user-configurable. If readings appear incorrect, check for leaks and then recalibrate the DP.
When performing the following procedures, wait for the flow computer display to stabilize before
entering the new values. If the flow computer is not in Calibration mode, the display will not
necessarily match the applied cell pressures.
Select Calibration on the tool bar to place the flow computer in Hold mode.
Select the measurement tube in the navigation tree.
1 2 6 | XSE RIE S G5 | 2 10 60 2 6MNAA